SNARC (spatial–numerical association of response codes) meets SPARC (spatial–pitch association of response codes): Automaticity and interdependency in compatibility effects

Concepts, including the mental number line, or addressing pitch as high and low, suggest that the spatial–numerical and spatial–pitch association of response codes (SNARC and SPARC) effects are domain-specific and thus independent. Alternatively, there may be dependencies between these effects, because they share common automatic or controlled decision mechanisms. In two experiments, participants were presented with spoken numbers in different pitches; their numerical value, pitch, and response compatibility were varied systematically. This allowed us to study SNARC and SPARC effects in a factorial design (see also Fischer, Riello, Giordano, &; Rusconi, 2013 Fischer, M. H., Riello, M., Giordano, B. L., &; Rusconi, E. (2013). Singing numbers?…?in cognitive space--a dual-task study of the link between pitch, space, and numbers. Topics in Cognitive Science, 5(2), 354–366. Retrieved from http://doi.org/10.1111/tops.12017[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Participants judged the stimuli on numerical magnitude, pitch, or parity (odd–even). In all tasks, the SNARC and SPARC effects had superadditive interactions. These were interpreted as both effects sharing a common mechanism. The task variation probes the mechanism: In the magnitude judgement task, numerical magnitude was explicit, whereas pitch was implicit; in the pitch judgement task, it was vice versa. In the parity judgement task, both dimensions were implicit. Regardless of whether they were implicit or explicit, both SNARC and SPARC effects occurred in all tasks. We concluded that by not requiring focal attention the common mechanism operates automatically.     

Binding “what” and “where” in auditory working memory: An asymmetrical association between sound identity and sound location

Contrasting results in visual and auditory working memory studies suggest that the mechanisms of association between location and identity of stimuli depend on the sensory modality of the input. In this auditory study, we tested whether the association of two features both encoded in the “what” stream is different from the association between a “what” and a “where” feature. In an old–new recognition task, blindfolded participants were presented with sequences of sounds varying in timbre, pitch and location. They were required to judge if either the timbre, pitch or location of a single-probe stimulus was identical or different to the timbre, pitch or location of one of the sounds of the previous sequence. Only variations in one of the three features were relevant for the task, whereas the other two features could vary, with task-irrelevant changes. Results showed that task-irrelevant variations in the “what” features (either timbre or pitch) caused an impaired recognition of sound location and in the other task-relevant “what” feature, whereas changes in sound location did not affect the recognition of either one of the “what” features. We conclude that the identity of sounds is incidentally processed even when not required by the task, whereas sound location is not maintained when task irrelevant.     

Memory for melody: infants use a relative pitch code

Pitch perception is fundamental to melody in music and prosody in speech. Unlike many animals, the vast majority of human adults store melodic information primarily in terms of relative not absolute pitch, and readily recognize a melody whether rendered in a high or a low pitch range. We show that at 6 months infants are also primarily relative pitch processors. Infants familiarized with a melody for 7 days preferred, on the eighth day, to listen to a novel melody in comparison to the familiarized one, regardless of whether the melodies at test were presented at the same pitch as during familiarization or transposed up or down by a perfect fifth (7/12th of an octave) or a tritone (1/2 octave). On the other hand, infants showed no preference for a transposed over original-pitch version of the familiarized melody, indicating that either they did not remember the absolute pitch, or it was not as salient to them as the relative pitch.     

Seeing what you hear: Visual feedback improves pitch recognition

The present study examined the effect of visual feedback on the ability to recognise and consolidate pitch information. We trained two groups of nonmusicians to play a piano piece by ear, having one group receiving uninterrupted audiovisual feedback, while allowing the other only to hear, but not see their hand on the keyboard. Results indicate that subjects for whom visual information was deprived showed significantly poorer ability to recognise pitches from the musical piece they had learned. These results are interesting since pitch recognition ability would not intuitively seem to rely on visual feedback. In addition, we show that subjects with previous experience in computer touch-typing made fewer errors during training when trained with no visual feedback, but did not show improved pitch recognition ability posttraining. Our results demonstrate how sensory redundancy increases robustness of learning, and further encourage the use of audiovisual training procedures for facilitating the learning of new skills.     

Functional ear (a)symmetry in brainstem neural activity relevant to encoding of voice pitch: a precursor for hemispheric specialization?

Pitch processing is lateralized to the right hemisphere; linguistic pitch is further mediated by left cortical areas. This experiment investigates whether ear asymmetries vary in brainstem representation of pitch depending on linguistic status. Brainstem frequency-following responses (FFRs) were elicited by monaural stimulation of the left and right ear of 15 native speakers of Mandarin Chinese using two synthetic speech stimuli that differ in linguistic status of tone. One represented a native lexical tone (Tone 2: T2); the other, T2′, a nonnative variant in which the pitch contour was a mirror image of T2 with the same starting and ending frequencies. Two 40-ms portions of f₀ contours were selected in order to compare two regions (R1, early; R2 late) differing in pitch acceleration rate and perceptual saliency. In R2, linguistic status effects revealed that T2 exhibited a larger degree of FFR rightward ear asymmetry as reflected in f₀ amplitude relative to T2′. Relative to midline (ear asymmetry = 0), the only ear asymmetry reaching significance was that favoring left ear stimulation elicited by T2′. By left- and right-ear stimulation separately, FFRs elicited by T2 were larger than T2′ in the right ear only. Within T2′, FFRs elicited by the earlier region were larger than the later in both ears. Within T2, no significant differences in FFRS were observed between regions in either ear. Collectively, these findings support the idea that origins of cortical processing preferences for perceptually-salient portions of pitch are rooted in early, preattentive stages of processing in the brainstem.